The 1 million elders living in residential care/assisted living (RC/AL) settings wish to age-in-place. However the progressive worsening of elders'functional limitations and disability in activities of daily living (ADL) threatens their plans to remain independent. Each year, ADL disability and other factors force approximately 21% of such residents to transfer to nursing homes instead of aging in place for longer periods. To slow the progression of ADL disablement in RC/AL residents, we need to better understand the factors affecting their disablement process. Physical activity (PA) is an important intra-individual factor that could affect physical function, and thus progression of ADL disability. But we have little data regarding PA behaviors and antecedents of PA behavior for RC/AL residents. In addition, the RC/AL environment itself is a salient extra- individual factor that may affect ADL disability, yet very little is known about how the environment interacts with residents'disability trajectories. The longitudinal study we propose, designed to address these gaps in knowledge, has four primary aims: (1) to examine PA levels and the influence of PA antecedents (perceived self-efficacy, perceived benefits, perceived barriers, and perceptions of aging) and extra-individual factors on pedometer-determined PA;(2) to determine the extent to which PA mediates the relationship between impairments and functional limitations, controlling for risk factors and pathology;(3) to explore the moderating effect of extra-individual factors (staff expectations for functioning and availability of PA programs) on the relationship between functional limitations and ADL disability;and, (4) to estimate the effect of change over time of impairments, functional limitations, and PA on ADL disability in RC/AL residents. From among 20 to 25 RC/AL facilities in central Missouri, a total of 245 consenting elders will provide data at three points in time (baseline, 6 months, and 12 months) in the form of questionnaires administered by interview, physical performance testing, and pedometer monitoring. Data about facility characteristics and resident profiles will be collected using facility surveys, medical record abstraction, and staff assessments. Analysis of Aim 1 involves descriptive statistics and correlational analyses. Aim 2 involves covariance structure analysis for calculating mediation. Aim 3 will again apply covariance structure modeling to explore moderation of the path model developed in Aim 2. Aim 4 will apply the model selection procedure using the backward selection procedure to select the optimal set of predictors. Additional exploratory aims will describe the types and frequency of self- reported PA program participation, and estimate the relationship between frequency of participation and both PA antecedents and PA level. This study will examine the interplay among PA, functional limitations, and ADL disability in the context of the RC/AL environment. Findings from this study will identify factors amenable to interventions to delay or prevent disability by changing PA behavior. PUBLIC HEALTH RELEVANCE: Increasing the proportion of elders who are able to age-in-place in, rather than transfer to a nursing home, could offer considerable savings in long term care spending, as well as satisfy consumer preferences. The proposed longitudinal study of PA and disability will determine targets for future interventions to slow the progression of ADL disability, a key reason elders living in RC/AL communities must relocate to nursing homes.